Air Source Heat Exchange System and Method Utilizing Temperature Gradient and Water

ABSTRACT

An air source heat exchange system and method in which usable heat is exchanged between a prescribed volume of a fluid heat exchange medium, preferably water, within a heat exchange chamber and ambient air outside the chamber. At least one and preferably a plurality of air source heat exchange chambers are provided, each having a volume for containing the prescribed volume of water dwelled within the chamber. The chamber has a chamber wall constructed of a material enabling effective heat transfer between the water dwelled within the chamber and adjacent ambient air outside the chamber. A circulation system circulates the water along a path of flow passing into and out of the volume of the chamber at a rate of flow so related to the prescribed volume of water that usable heat is transferred through the chamber wall, between the ambient air and the prescribed volume of water dwelled within the chamber.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/055,912, filed May 23, 2008, and PCT Application No. PCT/KR2009/002741, filed May 25, 2009, the entire disclosures of which are incorporated herein by reference thereto.

FIELD OF THE INVENTION

This invention relates generally to a system and method for heat exchange utilizing a temperature gradient between an air source and heat exchange units, and, more particularly, to an air source heat exchange system and method utilizing heat exchange units having improved efficacy of heat exchange using water as an intermediate heat exchange medium between ambient air and a heat exchange unit used in connection with a heat pump or a refrigerator.

BACKGROUND OF THE INVENTION

Air source heat exchange systems and methods have been in use for some time. In a typical air source heat exchange system, air is used to carry heat to and from a user's heat exchange site and adjacent atmosphere to absorb heat from or dissipate heat into ambient air.

Air source heat exchange systems are among the most convenient ways of achieving useful heat exchange in heating and cooling systems, and especially with respect to air source heat pump type systems requiring minimum labor, equipment and space to install.

Air is a very low density material with low heat content and low heat conduction potential compared to water. In order to increase heat exchange capacity, water-cooled-evaporative-air conditioning methods have been used to increase heat exchange efficiency by 60% to 70% compared to a conventional air source air conditioner (see http://www.toolbase.org/Technology-Inventory/HVAC/water-cooled-evaporative-air-conditioning). Utilization of this method in a heating mode is limited due to the possible freezing of water sprayed along heat exchange pipes at a user's site. Use of an anti-freeze compound is not feasible since recycling of the water after evaporation prohibits such use.

Generally, the utilization of an air source heat exchange system to conduct thermal exchange in an air-conditioner, a heat-pump or a refrigerator requires taking into account several inherent characteristics of such systems.

First, thermal exchange is dependent upon total heat exchange surface area of a heat exchange coil or other heat exchange components exposed to the air.

Next, thermal heat exchange is highly limited at low air temperatures, near the freezing point of water, due to the freezing of moisture found in the air, militating against use in a heating mode, i.e., temperatures near 40° F. Consequently, air source heat-pumps may require auxiliary electric heat to supply the heat required.

Further, heat exchange is limited by low heat content of the air, air having a specific heat of 6×10⁻⁶ cal./g of air. Heat exchange capacity is limited by the low density of air, namely, 0.001184 g/cubic centimeter. As such, the heat content of a volume of air compared to the same volume of water is the product of the two numbers.

In addition, heat exchange is governed by the conduction potential of the heat transfer medium adjacent the heat exchange coil or other heat exchange component, which medium is air in an air source heat exchange system. The heat conduction potential of air is 0.026, which is 1/23rd of that of water, namely, 0.60 k(W/m.K).

As one solution, a ground source heat pump has been utilized as an alternative and the most efficient way of achieving heat exchange, according to the DOE in the USA. However, geothermal heat exchange is limited by the conduction potential of the soil adjacent the heat exchange device and the limited extent of heat exchange surface. On the other hand, an air source heat pump is not so limited due to the ultimate convection potential of air.

Therefore, there is a need for an air source heat exchange system and method to substantially increase heat exchange surface area in air source heat exchange so as to enhance the overall efficiency of the system and method.

There is a need for an air source heat exchange system and method to operate in a lower temperature environment, especially when in a heating mode. Therefore, there is a need for an air source heat exchange system and method for increasing heat conduction potential to increase heat exchange capability. There is also a need for an air source heat exchange system and method that can take advantage of the ultimate convection potential of air to obtain increased heat transfer efficiency by using air.

Kinoshta et al [U.S. Pat. No. 4,545,214] and Inoue, et al [U.S. Pat. No. 5,904,052] each use water as a heat exchange medium as in a storage tank for an air conditioner by passing cooling medium, refrigerant, in a plurality of heat exchangers (copper piping), but fail to provide efficient recharging of the heat exchange medium in a storage tank and a sufficient increase in heat exchange area.

Yamada et al [U.S. Pat. No. 4,796,439] describes the use of a hot water tank and a cool water tank in a high building where heating needs and cooling needs compensate for one another. The invention mainly uses compensatory heat for a larger building. There exists the need for a cooling dominated or heating dominated efficient heat pump with an air cooled water source heat pump. But Yamada et al fails to provide efficient recharging of the heat exchange medium in a storage tank and a sufficient increase in heat exchange area, except for circulation between the top and the bottom of the building.

Forgy et al [U.S. Pat. No. 6,595,011] also describes a water based cooling system using evaporative cooling by air of water absorbed heat from a heat exchanger of an air conditioner. This method is limited to use in a cooling system.

In order to meet the above needs, an air source, water source heat pump and refrigerator using an air source heat exchange unit is disclosed. Conventional closed-loop water source heat pumps use geothermal energy to effect heat exchange. The present invention utilizes air source heat instead of geothermal heat to supply and dissipate heat to and from an air-source heat exchange unit. Distinguished from a geothermal heat unit, an air source heat exchange unit requires less unit body size and surface area to effect sufficient heat exchange (a technical problem addressed by the present invention).

SUMMARY OF THE INVENTION Solution to the Above Technical Problem

Temperature differences between ambient air and hot or cold water in a closed thin-walled bottle placed in the ambient air disappears within a few minutes or, at most, within a few hours, depending upon wind conditions (convection) encountered in the air. A hot material placed in water will lose heat much more quickly compared to that placed in air. Conversely, a cold material placed in water will gain heat much more quickly compared to that placed in air. The present invention takes advantage of these phenomena.

During a heating mode, the temperature differential between ambient air and a heat exchanger could cause freezing of moisture in the air at the heat exchanger coil or other component when the air temperature drops to a certain level, due to the extremely cold temperature of the heat exchanger component (i.e., 40° F.). The present invention uses water as a heat exchange medium between ambient air and a heat exchange component, which leads to a less likelihood of freezing.

An aspect of the present invention provides a unique heat exchange unit in an air source heat exchange system and method. The system and method include use of a plurality of heat exchange units placed in an open air space. A heat exchange unit is provided in the form of a chamber filled with a fluid heat exchange medium, the walls of the chamber being constructed of a material promoting effective heat transfer between the heat exchange medium and ambient air adjacent the chamber. The surface of the chamber may have several folds in the form of corrugations, or a curvature or other means for increasing air contact through an increase in air contact surface area. Use of corrugations or another curvature in a geothermal heat exchange system provides a minor advantage, since geothermal heat exchange is limited by the heat conduction potential of the geothermal mass over a limited distance. However, air is a free moving medium with a high convection potential so an increase in air contacting surface area can proportionally increase heat exchange effectiveness and efficiency. Each heat exchange unit also includes an input heat transfer conduit and an output heat transfer conduit for carrying the heat exchange medium, the input conduit proceeding through a surface of the heat exchange unit chamber at least a minimal distance into the chamber, and the output heat transfer conduit originating immediately at the other side surface of the chamber, preferably the farthest part. The heat exchange units are connected serially to one another in a continuous unbroken chain having a first heat exchange unit and a last heat exchange unit, such that the output heat transfer conduit from one heat exchange unit is the input heat transfer conduit for the next consecutive heat exchange unit, with the input heat transfer conduit for the first heat exchange unit originating at an output from a pump communicating with a user's heat exchanger, and the output heat transfer conduit for the last heat exchange unit terminating at an input for the user's heat exchanger. In an embodiment of the invention, the heat exchange units are placed in an open air space. The heat exchange medium is pumped into the first heat exchange unit through a corresponding input heat transfer conduit, then flows through a corresponding output heat transfer conduit which is the input heat transfer conduit for the next heat exchange unit in the chain, and then flows into the next heat exchange unit, and so on, until the heat transfer medium flows into the last heat exchange unit in the chain, from which the heat exchange medium flows through a corresponding output heat transfer conduit to the user's heat exchanger, and on to the pump, completing the cycle in an amount of time, measured by flow rates, greater than a few minutes or more depending upon the application. In an embodiment of the present invention, an air mover in the form of an air fan is added to the arrangement of the heat exchange units to facilitate a more rapid heat transfer by a forced convection of ambient air. The optional fan is activated when the temperature difference between the inlet and the outlet of the user's heat exchanger is below a predetermined system set temperature, i.e., 10° F. During circulation, water absorbs or dissipates heat from or to the ambient air.

In another aspect of the invention, an air source heat exchange unit supported heat exchange system and method is used in a refrigeration system and method. In an embodiment of the present invention, the compressor and a heat expansion unit of a refrigerator are located at the bottom of a user's refrigeration system. One or more of the back wall, side wall and bottom wall of the refrigeration unit of the system includes a heat exchange unit in the form of a relatively thin, wide chamber that holds water, or water with anti-freeze compound, inside the chamber. When refrigeration is required, heat is dissipated by the heat expansion unit to the water at the bottom of the chamber. Warm water moves naturally upwardly within the chamber and cold water moves downwardly by the natural convection created by temperature differences. The large surface area provided by the thin, wide chamber serves as an effective heat exchange surface between air outside and water inside.

In another aspect of the invention, the air source heat exchange unit supported heat exchange system and method is used in another refrigeration system. In an embodiment of the present invention, the compressor and a heat expansion unit of the refrigerator are located at the bottom of the refrigeration system. One or more of the back wall, the side wall and the bottom wall of the refrigeration unit of the system includes a baffled, thin, wide chamber that holds water, or water with an anti-freeze compound, inside the chamber. When refrigeration is required, heat is dissipated by the heat expansion unit to the water at the bottom of the chamber. Warm water is moved through channels established by the baffles within the chamber by a water circulating pump. The large surface area provided by the thin, wide chamber serves as an effective heat exchange surface between air outside and water inside.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a largely schematic diagram illustrating a typical air source heat exchange unit in the form of a chamber having a wall folded horizontally into horizontal corrugations, in accordance with an embodiment of the present invention;

FIG. 2 is a largely schematic diagram illustrating a typical air source heat exchange unit in the form of a chamber having a wall folded vertically into vertical corrugations, in accordance with an embodiment of the present invention;

FIG. 3 is a schematic diagram illustrating a typical air source heat exchange unit in the form of a chamber having a wall with no corrugations, in accordance with an embodiment of the present invention;

FIG. 4 is a largely schematic diagram illustrating a typical air source heat exchange system having a plurality of air source heat exchange units connected serially and arranged in a circular configuration, in accordance with an embodiment of the present invention;

FIG. 5 is a largely schematic diagram illustrating a typical air source heat exchange system having a plurality of heat exchange units connected serially and arranged in a circular configuration with an air fan and support, in accordance with an embodiment of the present invention;

FIG. 6 is a largely schematic diagram illustrating a typical air source heat exchange system having a plurality of heat exchange units in the form of thin, wide chambers connected serially and arranged in a tower-like vertically parallel configuration, in accordance with an embodiment of the present invention;

FIG. 7 is a largely schematic diagram illustrating a typical air source heat exchange system having a plurality of heat exchange units in the form of thin, wide chambers connected serially and arranged in a horizontally parallel configuration, in accordance with an embodiment of the present invention;

FIG. 8 is a largely schematic diagram illustrating a typical air source heat exchange system having a plurality of heat exchange units in the form of thin, wide chambers connected serially and arranged in a horizontally parallel, vertically stacked configuration, in accordance with an embodiment of the present invention;

FIG. 9 is a largely schematic diagram illustrating a typical air source heat exchange system as used in connection with a heat pump, in accordance with an embodiment of the present invention;

FIG. 10 is a largely schematic diagram illustrating a typical air source heat exchange system as used in a refrigeration system, in accordance with an embodiment of the present invention; and

FIG. 11 is a largely schematic diagram illustrating a typical air source heat exchange system as used in a refrigeration system with a water circulating pump, in accordance with an embodiment of the present invention.

DETAILED DESCRIPTION

In the following description, for purposes of explanation, specific numbers, materials and configurations are set forth in order to provide a thorough understanding of the invention. It will be apparent, however, to one having ordinary skill in the art, that the invention may be practiced without these specific details. In some instances, well-known features may be omitted or simplified so as not to obscure the present invention. Furthermore, reference in the specification to “one embodiment” or “an embodiment” means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. The appearances of the phrase “in an embodiment” in various places in the specification are not necessarily all referring to the same embodiment.

The present invention advantageously provides an air source heat exchange system and a method that enables increased efficiency, weather durability and easier installation and manufacture.

The present invention also provides for an air source heat exchange system and a method that take advantage of the high heat conduction potential and heat capacity of water.

The present invention also provides for an air source heat exchange system and a method that lowers the critical operating temperature of a heat pump in winter, so that an air source heat pump could be used in moderately cold regions.

The present invention also provides for an air source heat exchange system and a method that maximizes the convection potential of air to provide or dissipate heat with either no or only moderate use of a fan.

As a result of the innovative use of disclosed heat exchange units, the present invention greatly increases the effectiveness and efficiency of an air source heat pump compared to that of a geothermal heat pump system, without a marked increase in any significant cost of installation.

Thermal exchange efficiency, also known as thermal conductivity, is dependent upon the temperature differential between donors, total area of heat exchange, and heat transfer rate. As shown in the following equations, conductive heat transfer is expressed in equation (1) and convective heat transfer is expressed in equation (2), as follows:

q=kAdT/s  (1)

q=kAdT  (2)

Where q=heat transferred per unit time (W, Btu/hr), A=heat transfer area (m², ft²), k=thermal conductivity of the material [(W/m.K or W/m. ° C., Btu/(hr ° F. ft²/ft)] for equation (1) and k=convective heat transfer coefficient of the process (W/m.K or W/m. ° C.) for equation (2), dT=Temperature difference across the material (K or ° C., ° F.), and s=material thickness (m, ft).

The air source heat exchange system and method of the present invention are designed to take advantage of the high conduction potential of water compared to air in a limited surface area of a conventional heat exchange unit. In an embodiment of the present invention, the surface area of a heat exchange unit is expanded to increase the ratio between the area of the metal wall of the unit contacted by the heat inside the heat exchange unit and the external surface area of the wall of each of a plurality of heat exchange units.

In the present invention, an air source heat exchange system utilizing a heat pump is based on the principle of providing an optimal heat exchange in a gradient-based heat exchange system. The heat exchange capacity is proportional to the temperature difference between the thermal donor and the recipient. As presented in an embodiment of the present invention, an overall air-source heat exchange system is comprised of a plurality of air-source heat exchange units arranged serially in a successive order. So the temperature difference between donor (air when operating in a heating mode and water in an air source heat exchange unit when operating in a cooling mode) and recipient (water in the air source heat exchange unit operating in a heating mode and air when operating in a cooling mode) is greatest at the recipient air source heat exchange unit (from a heat pump) and lowest at the donor air source heat exchange unit (to the heat pump). As such, in the present invention, the water contained within each chamber of the serially connected heat exchange units is contained in a volume and flows at a rate of flow related to that volume sufficient to establish a dwell time during which the water in each chamber is subjected over enough time, usually several minutes, to allow a significant amount of heat exchange before returning to the heat pump.

In the present invention, the air source heat exchange system facilitates heat exchange by utilizing a large surface area, and does not always require an air mover such as an air fan. As such, this further enhances the efficiency of the air source heat exchange system.

FIG. 1 illustrates an exemplary air source heat exchange system 10 including a heat exchange unit in the form of a chamber 11. In accordance with an embodiment of the present invention, chamber 11 includes a wall 12 having a length L that is several feet long and a shallow diameter D to establish a relatively large surface area for heat exchange. Further, wall 12 is folded into several horizontal corrugations 14 to increase the surface area for heat exchange. Ports 2 and 3 provide an entrance and an exit for an air source fluid heat exchange medium circulated through the heat exchange unit by a circulation system which includes a pump 5 and conduits 6 and 7. Depending upon the location and orientation of a plurality of heat exchange units in the form of chambers 11, relative to an air source, port 2 can serve as either an entrance or an exit, while port 3 then serves as an exit or an entrance.

FIG. 2 illustrates another exemplary air source heat exchange unit in the form of a chamber 21. In accordance with an embodiment of the present invention, chamber 21 includes a wall 22 having a length L that is several feet long and a shallow diameter D to establish a relatively large surface area for heat exchange. Further, wall 22 is folded into vertical corrugations 24 to increase the surface area for heat exchange. As in the earlier-described embodiment, ports 2 and 3 provide an entrance and an exit for circulating an air source fluid heat exchange medium. Depending upon the location and orientation of a plurality of heat exchange units in the form of chambers 21, relative to an air source, port 2 can serve as either an entrance or an exit, while port 3 then serves as an exit or an entrance.

FIG. 3 illustrates still another exemplary air source heat exchange unit in the form of a chamber 31. In accordance with an embodiment of the present invention, chamber 31 includes a wall 32 having a length L that is several feet long and a shallow diameter D to establish a relatively large surface area for heat exchange. Here again, ports 2 and 3 provide an entrance and circulating an exit for an air source fluid heat exchange medium. Depending upon the location and orientation of a plurality of heat exchange units in the form of chambers 31, relative to an air source, port 2 can serve as either an entrance or an exit, while port 3 then serves as an exit or an entrance.

FIG. 4 illustrates an exemplary air source heat exchange system 40 in which a plurality of air source heat exchange units are shown in the form of chambers 11 arranged in a circular configuration. In accordance with this embodiment of the present invention, air source heat exchange system 40 is assembled from a plurality of air source heat exchange units selected from the air-source heat exchange units shown in FIGS. 1 to 3. In the illustrated assembly, conduits 41, 42 and 43 establish a water loop connecting adjacent chambers 11 serially with a heat pump 44. Conduits 42 and 43 are connected to an entrance and an exit, respectively, of heat pump 44. In the present embodiment, water from the exit of the heat pump 44 enters the assembly of chambers 11 through conduit 42 and passes through the serially connected chambers 11 via conduits 41 and then re-enters heat pump 44 through conduit 43. In the preferred size of each chamber 11 of the present embodiment, diameter D is about 0.5 ft and length L is about three feet, providing a volume of about four gallons. Use of the air source heat exchange system 40 over about ten minutes of heat transfer medium circulation time to a one-ton unit heat pump (12,000 BTU) requires a flow of approximately two gallons of water with about a 10° F. temperature difference in the water between entering and exiting heat pump 44, so the required rate of flow would be about 0.2 gallon per minute. As such, this embodiment of the present invention requires a number of chambers 11, each with a volume sufficient to establish a dwell time during which heat is transferred into or out of the water in each chamber 11 to enable the gain or dissipation of heat while passing through the chambers 11.

FIG. 5 illustrates another air source heat exchange system 40 with a plurality of air source heat exchange units in the form of chambers 11 arranged in a circular configuration, with the addition of a supplemental air fan 54. In accordance with the embodiment of the present invention, air source heat system 40 is assembled from a plurality of air source heat exchange units selected from the air-source heat exchange units shown in FIGS. 1 to 3. In the illustrated assembly, conduits 41, 42 and 43 establish a water loop connecting adjacent chambers 11 serially with heat pump 44. Conduits 42 and 43 are connected to the entrance and to the exit of the heat pump 44. An air mover in the form of air fan 54 is housed within a housing 55 located beneath air source heat system 40. In the present embodiment, water from the exit of heat pump 44 enters the assembly of chambers 11 through conduit 42 and passes through the serially connected chambers 11 via conduits 41 and then re-enters heat pump 44 through conduit 43. Use of the air source heat exchange system 40 in a one-ton unit heat pump (12,000 BTU), with about a 10° F. temperature difference in the water between entering and exiting heat pump 44, requires a rate of flow of water of about two gallons per minute, per ton. As such, this embodiment of the present invention requires a number of chambers, each with a volume sufficient to establish a dwell time during which heat is transferred into or out of the water in each chamber 11 to enable the gain or dissipation of heat while passing through the chambers 11. In the present embodiment, air fan 54 is actuated if the difference in water temperature between the entrance and the exit of heat pump 44 is below a system predetermined temperature, i.e., about 10° F., to increase heat exchange to and from the air.

FIG. 6 illustrates another air source heat exchange system 60 having air source heat exchange chambers 61, each in the form of a thin rectangular prism-like, or parallelepipedonal configuration, all placed in a vertically parallel arrangement. Chambers 61 are inter-connected serially by conduits 62 which connect adjacent chambers 61 serially between an inlet 63 and an outlet 64 for conducting water from and to the heat exchange system 60. Water from the exit of a heat pump (not shown) enters heat exchange system 60 through inlet 63, circulates through the serially connected chambers 61 via conduits 62 and then reenters the heat pump through outlet 64. During such circulation, heat is exchanged between heat exchange system 60 and adjacent ambient air. The preferred rectangular prism-like shape of each chamber 61 in this configuration is a thin, wide parallelepipedon. The illustrated configuration provides about nine square feet of surface area along each side 66 of a chamber 61, and a depth d of about one inch, which provides a total volume of about 5.7 gallons per chamber 61. In a one-ton unit, sufficient heat exchange is accomplished by circulating water at a rate of flow of about two gallons per minute, per ton, through seven serially connected chambers 61.

FIG. 7 illustrates another air source heat exchange system 60 having heat exchange chambers 61 in the form of thin, rectangular prism-shaped, or parallelepipedonal, chambers 61 placed in a horizontally parallel configuration. Chambers 61 are inter-connected serially by conduits 62, between an inlet 63 and an outlet 64, for conducting water from and to the heat exchange system 60. Water from the exit of a heat pump (not shown) enters heat exchange system 60 through inlet 63, circulates through serially connected chambers 61 via conduits 62, and then re-enters the heat pump through outlet 64. During such circulation, heat is exchanged between heat exchange system 60 and adjacent ambient air. The preferred rectangular prism-like shape of each chamber 61 is a thin, wide parallelepiped. The illustrated configuration provides about nine square feet of surface area along each side 66 of a chamber 61, and a depth d of about one inch, which provides a total volume of about 5.7 gallons per chamber 61. In a one-ton unit, sufficient heat exchange is accomplished by circulating water at a rate of flow of about two gallons per minute, per ton, through seven serially connected chambers 61.

FIG. 8 illustrates an air source heat exchange system 60 in which heat exchange chambers 61 are oriented horizontally and arranged parallel to one another, in a vertically stacked configuration. In accordance with the present embodiment, air source heat exchange system 60 is configured either as a single or as a multiple arrangement of one or more chambers 61 as shown in FIGS. 1 to 3, and equivalents. A water loop comprised of conduits 41 connects adjacent chambers 61, the water loop being connected to an entrance and to an exit of each chamber 61, respectively. In the present embodiment, water from an exit of a heat pump (not shown) enters air-source heat exchange system 60 at an entrance 42, passes serially through chambers 61 via water loop 41, and then re-enters the heat pump through an exit 43. The preferred minimum dimensions of each chamber 61 in the present embodiment include a diameter of about 0.5 ft and a length of about three feet, providing a volume of about four gallons. A one-ton unit (12,000 BTU), operating with a 10° F. temperature difference between entering and exiting water, requires a rate of flow of water of about two gallons per minute, per ton. As such, the present embodiment requires a number of chambers 61 to establish the gain or dissipation of heat while passing through the air-source heat exchange system 60. This embodiment of the present invention is adapted readily for use in a wall mounted air conditioner.

FIG. 9 illustrates an example of a connection between an air source heat exchange system 73 of the present invention placed in an ambient atmosphere 71, and a heat pump 72 within a user's enclosed environment 75, utilizing connecting conduits 742 and 743. In accordance with the present embodiment, the user's heat pump 72 receives water from air source heat exchange system 73 through conduit 742, heat is expelled into the heat pump 72, and then the water leaves heat pump 72 through conduit 743 to re-enter air source heat exchange system 73. Water passes through air-source heat exchange system 73 to receive heat from ambient air before re-entering heat pump 72, when operating in a heating mode. In a cooling mode, the water absorbs heat from heat pump 72 and releases heat into air source heat exchange system 73. The preferred total circulating time is about twenty to thirty minutes. An air fan 74 is actuated when the temperature difference between water in conduit 742 and water in conduit 743 is below a predetermined system set value.

FIG. 10 illustrates, largely diagrammatically, an example of the use of an air source heat exchange system 80 in a refrigerator 81 having a heat expansion unit 82, a lower bottom wall 83, a back wall 84, a side wall 85 and a compressor 87. In the present embodiment, air source heat exchange system 80 includes a heat exchange chamber 90 which extends along the lower bottom wall 83 and along the back wall 84. The condensing unit of the refrigerator 81 is not shown. Chamber 90 is filled with water and includes a lower bottom portion 92 and an upper back portion 94. Heat expansion unit 82 is placed within the lower bottom portion 92 of chamber 90. In an active mode, compressor 87 emits hot refrigerant into heat expansion unit 82. Hot refrigerant in heat expansion unit 82 dissipates heat into water contained in lower bottom portion 92 of chamber 90. Heated water in lower bottom portion 92 rises naturally to move into a higher position within upper back portion 94 of chamber 90. After dissipating heat into ambient air adjacent upper back portion 94, the water cools and moves downward into the lower bottom portion 92 of chamber 90 in exchange for hot water. Circulation of the water is depicted by arrows 95. The total volume of water in the chamber 90 may exceed somewhat the volume of water required to operate refrigerator 81 for one hour, to gain 10° F. without exchanging heat with external ambient air. Most refrigerators 81 will require a total of less than five gallons of water to operate.

FIG. 11 illustrates, largely diagrammatically, another example of the use of an air source heat exchange system 80 in a refrigerator 81 having a heat expansion unit 82, a lower bottom wall 83, a back wall 84, a side wall 85, a compressor 87 and a water circulating pump 88. The condensing unit of refrigerator 81 is not shown. As before, air source heat exchange system 80 includes a heat exchange chamber 90 which extends along the lower bottom wall 83 and along the back wall 84. Chamber 90 is filled with water and includes a lower bottom portion 92 and an upper back portion 94. Heat expansion unit 82 is placed within the lower bottom portion 92 of chamber 90. In an active mode, compressor 87 emits hot refrigerant into heat expansion unit 82. Hot refrigerant in heat expansion unit 82 dissipates heat into water contained in lower bottom portion 92 of chamber 90. Heated water in lower bottom portion 92 rises naturally to move into a higher position within upper back portion 94 of chamber 90. The upward movement of heated water from lower bottom housing 83 to the higher position within upper back portion 94 is assisted by water pump 88. In the present configuration, upper back portion 94 is divided by several baffles 96 to establish a serpentine flow path and a concomitant stepwise temperature gradient. After dissipating heat into ambient air, the water cools and moves downward into the lower bottom portion 92 in exchange for hot water in the lower bottom portion 92. The water is circulated by the water circulating pump 88. The total volume of water in chamber 90 may exceed somewhat the volume of water required to operate refrigerator 81 for one hour, gaining 10° F. without exchanging heat with external ambient air. Most refrigerators 81 will require a total of somewhat less than five gallons of water, and preferably about three gallons of water, to operate according to the energy star guide.

This system can be used in areas where there is no extreme cold.

Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims. 

1. An air source heat exchange system in which usable heat is exchanged between a prescribed volume of a fluid heat exchange medium dwelled within an air source heat exchange unit and ambient air outside the heat exchange unit, the system comprising: at least one air source heat exchange chamber having a volume for containing the prescribed volume of fluid heat exchange medium dwelled within the heat exchange unit; the chamber having a chamber wall constructed of a material enabling effective heat transfer between the fluid heat exchange medium dwelled within the chamber and adjacent ambient air outside the chamber; and a circulation system for circulating the fluid heat exchange medium along a path of flow passing into and out of the volume of the chamber at a rate of flow so related to the prescribed volume of fluid heat exchange medium that usable heat is transferred through the chamber wall, between the ambient air and the prescribed volume of fluid heat exchange medium dwelled within the chamber.
 2. The air source heat exchange system of claim 1 wherein the chamber wall includes an outer surface of extended surface area for being exposed to the ambient air.
 3. The air source heat exchange system of claim 2 including an air mover for moving the ambient air across the outer surface of the chamber wall.
 4. The air source heat exchange system of claim 1 wherein the fluid heat exchange medium is water and the circulation system includes a water pump for pumping the water along the path of flow, the path of flow extending between an outlet from the water pump to the chamber, and then from the chamber to an inlet to the water pump.
 5. The air source heat exchange system of claim 4 wherein the chamber wall includes an outer surface for being exposed to the ambient air, and the air source heat exchange system includes an air mover for moving the ambient air across the outer surface of the chamber wall in response to a temperature difference between the inlet to the water pump and the outlet from the water pump less than a predetermined set value.
 6. The air source heat exchange system of claim 1 including a plurality of said air source heat exchange chambers interconnected serially such that the fluid heat exchange medium is circulated along the path of flow sequentially from one of the plurality of air source heat exchange chambers to a next consecutive air source heat exchange chamber of the plurality, along the path of flow.
 7. The air source heat exchange system of claim 6 wherein each air source heat exchange chamber includes a chamber wall having an outer surface of extended surface area for being exposed to the ambient air.
 8. The air source heat exchange system of claim 7 including an air mover for moving the ambient air across the outer surface of each chamber wall.
 9. The air source heat exchange system of claim 6 wherein the fluid heat exchange medium is water and the circulation system includes a water pump for pumping the water along the path of flow, the path of flow extending between an outlet from the water pump to the serially connected air source heat exchange chambers, and then from the serially connected air source heat exchange chambers to an inlet to the water pump.
 10. The air source heat exchange system of claim 9 wherein each chamber wall includes an outer surface for being exposed to the ambient air, and the air source heat exchange system includes an air mover for moving the ambient air across the outer surface of each chamber wall in response to a temperature difference between the inlet to the water pump and the outlet from the water pump less than a predetermined set value.
 11. A refrigeration system including an air source heat exchange system of claim 1, the refrigeration system comprising: a refrigerator having a back wall, a side wall and a bottom wall; and wherein the chamber has a thin, wide configuration and includes a lower bottom portion and an upper portion, both the lower bottom portion and the upper portion communicating with one another for containing the fluid heat exchange medium, the lower bottom portion of the chamber being located along the bottom wall of the refrigerator, and the upper portion extending along at least one of the back wall and the side wall of the refrigerator for exposure to ambient air; the refrigerator including a heat expansion unit located at the lower bottom portion of the chamber, such that upon operation of the refrigeration system, heat is dissipated from the heat expansion unit into the fluid heat exchange medium in the chamber, adjacent the lower bottom portion of the chamber for conduct to the upper portion of the chamber.
 12. The refrigeration system of claim 11 wherein the fluid heat exchange medium is water and the refrigeration system includes a water pump for circulating the water along a circulation path extending through the lower bottom portion and the upper portion of the chamber.
 13. The refrigeration system of claim 12 wherein the prescribed volume of fluid heat exchange medium is about three gallons.
 14. The refrigeration system of claim 13 wherein the thin, wide configuration of the chamber has a thickness of about one-half to one inch.
 15. The refrigeration system of claim 14 wherein the chamber includes a plurality of baffles within the upper portion of the chamber.
 16. An air source heat exchange method in which useful heat is exchanged between a prescribed volume of a fluid heat exchange medium dwelled within an air source heat exchange unit, and ambient air outside the heat exchange unit, the method comprising: providing at least one air source heat exchange chamber having a volume for containing the prescribed volume of fluid heat exchange medium dwelled within the heat exchange chamber, the chamber having a chamber wall constructed of a material enabling effective heat transfer between the fluid heat transfer medium dwelled within the chamber and adjacent ambient air outside the chamber; and circulating the fluid heat exchange medium along a path of flow passing into and out of the volume of the chamber at a rate of flow so related to the prescribed volume of fluid heat exchange medium that usable heat is transferred through the chamber wall, between the ambient air and the prescribed volume of fluid heat exchange medium dwelled within the chamber.
 17. The air source heat exchange method of claim 16 wherein the chamber wall includes an outer surface of extended surface area, and the surface area is exposed to ambient air moved across the outer surface of the chamber wall.
 18. The air source heat exchange method of claim 16 wherein the fluid heat exchange medium is water.
 19. The air source heat exchange method of claim 18 wherein the volume of fluid heat exchange medium dwelled within the chamber is about four gallons and the rate of flow is about two gallons per minute, per ton.
 20. The air source heat exchange method of claim 16 including providing a plurality of said air source heat exchange chambers interconnected serially such that the fluid heat exchange medium is circulated sequentially from one of the plurality of air source heat exchange chambers to a next consecutive air source heat exchange chamber of the plurality, along the path of flow.
 21. The air source heat exchange method of claim 20 wherein the fluid heat exchange medium is water.
 22. The air source heat exchange method of claim 21 wherein the volume of fluid heat exchange medium dwelled within the chamber is about four gallons and the rate of flow is about two gallons per minute, per ton. 